package com.example.demo.config;

import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 解决跨域
 * 
 * @author zbj
 */
@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {

	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {

		HttpServletResponse response = (HttpServletResponse) res;
		HttpServletRequest request = (HttpServletRequest) req;
		response.setHeader("Access-Control-Allow-Origin", "*");
		response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
		response.setHeader("Access-Control-Max-Age", "3600");
		response.setHeader("Access-Control-Allow-Credentials", "true");
		response.setHeader("Access-Control-Allow-Headers", "*");
		if (request.getMethod().equals(HttpMethod.OPTIONS.name())) {
			response.setStatus(HttpStatus.NO_CONTENT.value());
		} else {
			chain.doFilter(req, res);
		}
	}

	@Override
	public void init(FilterConfig filterConfig) {
	}

	@Override
	public void destroy() {
	}

}
